The invention relates to a method for deregistering a user registered at a terminal via registration data, which terminal is provided with a terminal memory in which the registration data are stored in response to identification information to be supplied, registration location data to be supplied to a network being stored in a memory field of a location memory means of the network.
Such a method is generally known and generally takes place after the user has registered himself at the terminal via registration data.
The registration takes place in the case of a not very advanced terminal, for example, by placing a smart card in the terminal, after which the terminal obtains identification information from the smart card and feeds it to the network. In response thereto, the network stores registration location data in the memory field of the location memory means. The deregistration then takes place in the abovementioned example of the not very advanced terminal by removing the smart card from the terminal, after which the terminal feeds deregistration data to the network. In response thereto, the registration location data in the memory field of the location memory means are declared invalid. If the user moves without removing his smart card from the terminal when he does so, this only has the consequence that incoming telephone calls for this user are incorrectly routed to the terminal, that user cannot register himself at another terminal without his smart card and that another user cannot register himself at the first terminal mentioned. However, the other user can, of course, remove the smart card of the first user and then register himself at the terminal, which has the consequence that incoming telephone calls for the first user mentioned are no longer routed to any terminal at all.
In the case of a more advanced terminal, the registration takes place, for example, by accessing the smart card by means of a card reader associated with the terminal, the terminal obtaining the identification information from the smart card via the card reader and storing identification data in the terminal memory. The terminal feeds the identification data to the network which, in response thereto, stores the registration location data in the memory field of the location memory means. In the example mentioned of the more advanced terminal, various users could even register at the same terminal, the identification data associated with further users also being stored in the same terminal memory. The deregistration could in this case take place by accessing the smart card again by means of the card reader associated with the terminal.
Such a method has, inter alia, the disadvantage that, if the user moves without accessing his smart card again by means of the card reader, this not only has the consequence that incoming telephone calls intended for the user are incorrectly routed to the terminal, but also that the terminal memory is unnecessarily taken up by invalid information, as a result of which other users can no longer register at the terminal at a given instant.